• American heart journal · Aug 2001

    Comparative efficacy of fibrinogen and platelet supplementation on the in vitro reversibility of competitive glycoprotein IIb/IIIa (alphaIIb/beta3) receptor-directed platelet inhibition.

    • Y F Li, F A Spencer, and R C Becker.
    • Cardiovascular Thrombosis Research Center, Laboratory for Vascular Biology Research, University of Massachusetts Medical School, Worcester, MA 01655, USA.
    • Am. Heart J. 2001 Aug 1;142(2):204-10.

    BackgroundPlatelet surface glycoprotein (GP) IIb/IIIa (alphaIIb/beta(3)) receptor inhibition, by preventing fibrinogen binding and platelet aggregation, concomitantly attenuates arterial thrombotic capacity and impairs protective hemostasis, 2 divergent platelet-dependent processes. Because the currently available Food and Drug Administration-approved small molecule GP IIb/IIIa receptor antagonists are considered "competitive" inhibitors and because there is limited information on the reversibility of platelet inhibition by fibrinogen or platelet supplementation, the following series of in vitro experiments were performed.Methods And ResultsWashed platelets from 24 healthy volunteers were suspended in Tyrodes buffer and incubated with achievable (in vivo) steady-state concentrations of either tirofiban or eptifibatide before activation with TRAP (thrombin receptor agonist peptide) (15 micromol/L). Platelet aggregation was inhibited by 40% to 50%, but reversal was achieved by fibrinogen supplementation in a concentration-dependent manner. In a separate series of in vitro experiments, platelet inhibition exceeding 90% was established with tirofiban (average concentration 9.28 microg/L) and eptifibatide (average concentration 95.4 microg/L). Recovery of platelet aggregation to at least 50% was achieved after the addition of fibrinogen (0.76-0.80 g/L), platelets (2.4 x 10(11)/L), or their combination. There was an inverse relationship between plasma baseline fibrinogen and the amount of supplemental fibrinogen required to restore platelet aggregability (r = -0.60, P <.01).ConclusionsThe reversibility of GP IIb/IIIa-directed platelet inhibition is influenced by cell surface receptor availability and the intrinsic pharmacodynamic mechanism of action. Fibrinogen supplementation with fresh frozen plasma or cryoprecipitate either alone or in combination with platelet transfusion, represents an important and readily available treatment consideration for restoring hemostatic potential and managing major hemorrhagic complications associated with the administration of small molecule competitive GP IIb/IIIa receptor antagonists.

      Pubmed     Full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…

What will the 'Medical Journal of You' look like?

Start your free 21 day trial now.

We guarantee your privacy. Your email address will not be shared.